Colombian Nairo Quintana (Movistar) says his guard had dropped when Chris Froome (Sky) attacked after the top of the Col de Peyresourde this afternoon. Froome rode free solo on the final descent and gained 23 seconds at the finish in Bagnères-de-Luchon.

Quintana chased with teammate Alejandro Valverde, Tejay van Garderen and Richie Porte (BMC Racing), Adam Yates (Orica-BikeExchange) in the white jersey and other favourites on the 15.5-kilometre descent. They pulled the gap from 23 to 13 seconds at the finish. Froome, though, with the stage win earned 10 bonus seconds and the yellow jersey.

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Journalists waited in the 36-degree heat next to the blue Movistar bus when Quintana arrived. He spoke in his usual low-tone, but one that indicated he erred.

“I was reaching over for a water bottle to refresh myself, and Froome took advantage of this moment to attack,” Quintana said. “He went down, and got away from us, and took some seconds on all of us.

“I hope it’s no decisive. I thought we could catch him on the descent, and Alejandro [Valverde], but it wasn’t enough.

“Today was harder than we expected, and on the last part, I let my guard down.”

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Froome leads the overall by 16 seconds on Yates in second overall. Quintana sits in sixth place at 23 seconds with the other favourites.

“Yeah, for sure it was a surprise,” Team Manager Eusebio Unzué said. “He was always there behind Froome, but then Froome went.”

Team Sky would not say if it was planned, but Sergio Henao appeared to position Froome at the right moment for the top of the climb. Froome also raced with a 54-tooth chainring today on his black Pinarello.

“It was a good strategy by Team Sky. He got in by 13 seconds and took bonus. I’ve never seen Froome attack like that on the descent. Nairo was there in all the climbs, but there he could not follow,” Unzué added.

“This was the first big battle in the high mountains. We saw a spectacular finish today, with the difference made on the descent. Probably no one expected that. Today was like that. I hope this time won’t be the definitive split for us when we get to Paris.”

Tomorrow, the Tour de France covers the hardest of its three Pyrenean mountain stages. In the final of the ninth stage in Andorra, it covers the Col de Beixalis and finishes up to Arcalis.

“These are only the first mountain stages, and tomorrow will certainly be more decisive,” Quintana said. “I still have a lot of confidence.”